I think I found your answer: http://www.google.com/url?sa=t&rct=j&q=ohio%20domestic%20abuse%20laws&source=web&cd=2&ved=0CEAQFjAB&url=http%3A%2F%2Fwww.ohiolegalservices.org%2Fpublic%2Flegal_problem%2Fdomestic-violence%2Fdomestic-violence%2Fcriminal-domestic-violence%2Fqandact_view&ei=FuyyUNe3EYeH0QHCpYGIBA&usg=AFQjCNG8hQsdgbtd4QkOew6fPNX576or_Q Can the police arrest both parties—the man and the woman—for domestic violence? Yes, but Ohio law strongly discourages that practice. Under Ohio’s preferred arrest law, in cases where law enforcement officers determine that both the man and the woman committed domestic violence, the officer should determine which party is the “primary physical aggressor.” RC 2935.03(B)(3)(b). Law enforcement officers are not prohibited from arresting both persons who engage in domestic violence against each other, but in most cases the officer should only arrest the primary physical aggressor. In determining which person is the primary physical aggressor, the officer should consider the following factors: